Brake-shoe.



. y 'cna'nriisw .Anmzmisr or CHICAGO,l ILLINOIS; AssrGNoit BYMESNE ASSIGNMENTS',

'ro THE' munizioni BBAKEJS y 17, WABEQA onPonA'rIoN'oFfDELAwanE. .y

, www md iai' 25,1916 bassi, i o f Be it known that 1I y:CHA vv its ABM- BRUs'i-, a'citizen'of thel n nite'd States,'"fiesid ing 'I at Chicago5 in the" county 'offCook and State fof Illinois, have 'invented "al I Certain l new and fusefullmprovement in 'Brak- Shoesfofj which the following is a full,fc1ear5 concise,v and exact description, reference be-'r ing khad" totheffaccompanying drawings; formingfal part of this' specification.l i

f n My invention-'relates to 'brake shoesi'fand has'f-forits ob ect the provision of an im-- proved shoe o such construction that itis rmu'ch lighter thanshoes hithertoproduced,A and` lyety produces the necessary ffrictional resistance to serve its'purposeQ l i f `@Asi-well understood,-v a'fbrakeshoe isused` tov retard 'the motion of a vehicle, and the retardin" eifectgis'due to thefriction `betweeny t e applied` brakef shoesV and y*the V A wheels, l"oijany` iven"casei'theamountflof f friction thcretar ingkfeifect" yproduces`'-,will

dependen the materials-of which they 'shoes' areklniade,k .the kweight of the car, andthe pressure of the shoe agains'tnthe wheel. Ac#

cording tol-the laws of :friction wek find that i friction@ is fdirectly proportional-f tovv 'the y weight" or fforce applied,y but y is independenty (ififthei surfaces zi in contact, the total fric/e tion' remaining i thesame (withinpractical tirezlfthe running surfaces are in Contact y The coeilcientof riction-isfused to fi ure thezfriction between two: surfaces infsli ing v contact,y and is determined bythe nature of 'f the materialsdin contact.` Rotationv'o the 'i-wheels in. thefcajsef of a;

moving. I train iis .caused `the 1 adhesionL fof" y Y u Furthermore, the coefficient of:k A frictionvaries with the I speed and length of non 1a FOUNDRY c'oMrANY, or WILirrmcf'roir,` DELA:

is not supplied' thetirainfwi11s1owdwn and l" finally stop: *Ifthe pressureon the shoejis gradually increased thefriction :between d wheel and shoey becomes `,greater and greater until `itfiirst equalsiandthen exceeds ythe adI` hesion betweenv the` tires and therail.

f Asisewdfabqe; the tiri-e in .cncacbfwirh *the rail beingat rest'fmomentarily with reference t't-l1keA forward;l motion" of,l tlie',"train,l the adhesion jjinust be caused by y'frictioni l pas vVVhenthe [friction of the shoe'equalsthe v adhesive` foroe'tofthe rails, {the'iwheels skid'k alongl Ithe rails and' the resistance l to its motion fisjequaljfto the 4frictional resistance to the sliding motion vof` the wheels `alofng two-@cases f 1654 the' rails. 'Thusflitis (seen there/arei shoe g against Vthe; wheel which is f .measured by'fthe coeiiicient of"A friction betweenV the against' the shoefn y Second# The skidding of the wheels along v the .rail which Aforce lis 'measured bythe coefficient of Efriction between," rail and'wheel' bytheweightjbn'the wheelr:

FromFthe foregoing actwe see *therf rail l acts-in'fevery'sense"the Vsameas'a brake shoe andbearsout the second ,law of friction that friction s'ndepn'dent of the extent onfthesurfaces iny slidingcontact??I Inany givenicasethe-retardingf'power is limited 1 tothe adhesive force ofthegwhcel tothe'` rail, in', which lcase the extent of-theis'ur-L- faces inrfslidin'g contact is practically,` only aline the `width"-`of theirail( "if i" Y' -11I-ind that, vin accordance withgthejabove facts @I amy enabled; 'tofconstructat brake shoe-` oflfwhichythe arealof" the material pressingl against the vwheel V-is largely reduced without sacrificing any fof fthe frictioiial'` shoes.; .f

'Bef described ymore in detail ,later I-useja o sizefas-that :of the standardy brake slices.l 1 I reduce A.theareavoffcontact, thus saving a* large: amountiofimaterial, lmakingthe"brake value, and 4yeti insuring longer' life ofthe AMLInwonefoilnoft4 Y brake shoe whose outline' 'slthef` saine" inf 'f f howeverprovidef-holes in this brake shoe to y n Y view of a brake shoe constructed in co'i'dance with 'my' invention;

Fig. 2 is a front face view thereo.- Fig. 3 is a view similar'toxFigfQ of a moded-fornnand p' n Y Fig. 4 is a. view similar to F 2 tof a modiied form, and y f Fig.'5, Fig. 6 and Fig. 7 are .e views of rfurther modifications of lmy imf 20 proved shoe.k v y v i My improved brake shoe consists of the shoe portiony 1 and the back portion 2 .as well understood. In accordance with my invention Iprovide in the face of, the shoe portion 1 a plurality of holes 3, 3, which holes eX- tend backwardly into the brake shoe proper. These holes, as will be readily apparent, leave the brake shoe with a great deal less material than it has hitherto been customary to use. The reduction ofthe area of contact does not militate against the frictions), value of the shoe. However, the yarrangement of this plurality of holes permits the edges of the material around these holes to be chilled during theprocess ofcasting due to the normal chill which the material is given. my improved shoe the holes are formed by the pattern in the mold by havingthemolten metal flow against the edges of the sand, thus to form the holes in the shoe body, espe cially by using a special mixture of metals with which to make and cast the shoe body, thus reducing the ,cost of manufacturing shoes .very substantially and getting the chilling effect and its consequent extended life simply and cheaply. The shoe likewise has an equal distributionof chilled sections throughout its body and thus presents a more homogeneous structure. The holes furthermore allow A the ywaste, metal of the shoe and of the wheels to be largely accumulated therein asis readily apparent. In this manner a shoe hav' dierent degrees of hardness is obtainednnd the hard rtions of the shoe are the elements which increasey the life of the shoeby saving the wear ofthe softer portions between those chilled ksec'- tions, `which softer portions in connection with `the chilled portions give the necen'yr frictional qualities. v

: In Fig. 3, I show a shoe lhaving however the holes 4,4 larger and, preferably as shown, some of which are .ta SlmwingtheL use of an expanded metal;

embedded in the sides and ends of the shoe to strngtlien it and tohold fracturedparts n 4, I Show a similar view, the shoe however being provided with diagonall Hplacedfholes again stugge both toward the face and back of the holes in the shoe shown-in lge i Figi shows a "structure in which the holes extend through from amish heb d thi shoeitohe other sida s Itis of 'limits immaterial what Lgeyle Yor outline, is given. fholesqeo longen the general pnoipleeabove set forth arevr adhereda to. I; :merel f'ow the two modifications to pendent upon a partieulbrkind of reeel-.for hole lto accomplish .the object desired..

HavinghoWevmtbs sdescribedsone which my invention meytelne, theel shim eenen and V 6 is a. sectional view showi one of 75 assumed" ng 3 and desire to secure 9o l1. brake-shoe spring fue ma l body, Presenting; i surface and having-,m phi-,1' f wfofml distributediim um extending. inte said bodyA tbl whereby v weightioi the shoe ielegnenedwithone de' u stroying itseicienny Y wm-gigas peionrrovidediwicna plannery heini 100 extending .from frontlf-tereertheree me osaidholes being straight andsomehiviredgw s ape.. vf lv I f f M 3. A. brakefsboe havingmfwea #ieee portion provided with sphxlity extending from front to marfth'ereof, seme of seid holes being stmightandome wedge shape, and amlid portion etthebaeblof nidi holes.

.hun los portion provided with a plmhty' heb'. ex

distribntedinsteggu'ed nelatien out.. saidfweann' gface im' omid being straight and pnmllel lithaoh other` and ythemed;v of mid holas Bm'ngfwedgeslpaandasolidporenitu er!l s .wearing face I s 5.v A bnlm shoecomprising e'` presentingl e weaning bod '.,pmlllgf LL.; suwa'odbavmgm Spin il 391311,44?A l f B u j uuifurruly diruriluuuuik iu :raid surfufuud traps embedded iu Suid had; surrounding 1o 1 `extending into saidfbodyand strengthenin `the area, rovided with opemn and adjal opening'sand the ends of the shoe. i

strips embedded in the shoe. between sai centv the sides and ends of the's oe.k Inwitness whereof, I hereuntosubscribe '7g A brake shoey comprising e` cast metel my neme this 23rd dey of Mey, A. D. 1916.

bod presenting a homogeneous wearing CHARLESKW. ARMBRUST. sur ace, and having e pluralit ofiopenings Witnesses: p f `uniformly distributed in', sai surface `and A. L. VJONES, n Y extending `into said body and strengthening' HAznLA. Joins. u r fui copies` of this patentmy be :obtained for nveeents eeoh'by addressing the commissioner o! Iatentl/Q- y v r welhingtomn i 

